The morphology and host-specificity of the histophagous apostome ciliate Vampyrophrya pelagica infecting pelagic copepods in the Seto Inland Sea, Japan, were intensively investigated. Four stages were reconfirmed in the life cycle of the ciliate. A mature cell within the phoront bears cilia ready for quick excystation, and unique lamellar structures in the cytoplasm appear to be precursors of food vacuole membranes. These lamellar structures completely disappear in the fully grown trophont. The phoronts were attached to the ventral surface of the copepod prosome or legs, but were almost totally absent on the urosome. The number of phoronts per copepod was up to 43 for the adult female of Paracalanus parvus s.l. Phoront attachment was found irrespective of developmental stage and sex of P. parvus s.l., although the early copepodid stages were less frequently infected than the later stages, and the adult female was more intensively infected than the adult male. There was a marked seasonal change in prevalence and host-specificity of the phoronts. From middle summer to early winter, P. parvus s.l., Acartia pacifica, Tortanus forcipatus, Euterpina acutifrons, and Corycaeus affinis were frequently infected, while Oithona spp. and Microsetella norvegica were rarely infected, whereas from late winter to early summer, phoronts were detected only on the large-sized calanoids, Calanus sinicus and Euchaeta plana. This may be explained by a combination of longevity and molting of copepods, turnover time of the apostome life cycle which depends on water temperature, and seasonal changes in the abundance and food selectivity of predatory chaetognaths. Considering the high prevalence of apostome ciliates on not only copepods but also other crustaceans in the world oceans, the ecological influence of these ciliates on marine ecosystems should be re-evaluated. KEY WORDS: Apostome ciliate· Vampyrophrya pelagica · Copepod · Parasite · Host · Histophagy · Trophodynamics Resale or republication not permitted without written consent of the publisherMar Ecol Prog Ser 282: [129][130][131][132][133][134][135][136][137][138][139][140][141][142] 2004 are epibionts which live exclusively on the copepod body surface (Steuer 1932, Sewell 1951, Hiromi et al. 1985, Nagasawa 1986, Fernandez-Leborans & TatoPorto 2000.Apostome ciliates are known to infect a wide variety of marine and freshwater crustaceans including shallow-and deep-water copepods (Chatton & Lwoff, 1935, Sewell 1951, Kudo 1966, Lindley 1978, Grimes & Bradbury 1992, Ohtsuka et al. 2003. The complex, unique life cycle of the apostome ciliate Vampyrophrya pelagica (Chatton and Lwoff) on coastal copepods was elucidated by Grimes & Bradbury (1992). According to them, 4 functionally different stages are recognized in this apostome: phoront (resting stage), trophont (feeding stage), tomont (division stage), and tomite (infective stage). Excystation of the trophont is triggered either by injury to the host (single-host cycle) or by predation by invertebrate predators such as...
A colorless euglenoid flagellate Peranema trichophorum shows unique unidirectional gliding cell locomotion on the substratum at velocities up to 30 micro m/s by an as yet unexplained mechanism. In this study, we found that (1) treatment with NiCl(2) inhibited flagellar beating without any effect on gliding movement; (2) water currents applied to a gliding cell from opposite sides caused detachment of the cell body from the substratum. With only the anterior flagellum adhering to the substratum, gliding movement continued along the direction of the anterior flagellum; (3) gentle pipetting induced flagellar severance into various lengths. In these cells, gliding velocity was proportional to the flagellar length; and (4) Polystyrene beads were translocated along the surface of the anterior flagellum. All of these results indicate that a cell surface motility system is present on the anterior flagellum, which is responsible for cell gliding in P. trichophorum.
BACKGROUND:The prevalence and prognostic value of human papillomavirus-related oropharyngeal squamous cell carcinoma (OPSCC) in Japan has not been evaluated. METHODS: Over a 12-year period, the authors used immunohistochemistry to evaluate the expression of p16 (a cyclin-dependent kinase inhibitor and tumor suppressor) in samples from 173 patients with OPSCC at a single institution and to determine its prevalence and influence on disease prognosis. RESULTS: The prevalence of p16-positive OPSCC was 33.7% in tonsillar carcinoma, 28.6% in tongue base carcinoma, 0% in posterior wall carcinoma, and 18.8% in soft palate carcinoma. The prevalence of p16-positive OPSCC tumors increased from 15.2% during 2000 to 2003 up to 33.3% during 2008 to 2011; during the same periods, among nonsmokers, the prevalence of p16-positive OPSCC tumors increased from 21.2% to 27.8%; and, among nondrinkers, prevalence increased from 6.1% to 25%. Multivariate analysis identified p16 expression and alcohol consumption as significant, independent prognostic markers of OPSCC. CONCLUSIONS: The current results suggest that the incidence of human papillomavirus-related OPSCC in Japan is increasing and indicate that p16 expression and alcohol consumption may be significant prognostic markers of survival for patients with OPSCC in Japan. Cancer 2013;119:2005-11. V C 2013 American Cancer Society.KEYWORDS: oropharyngeal carcinoma, head and neck squamous cell carcinoma, p16, human papillomavirus, alcohol consumption, Japan. INTRODUCTIONTobacco smoking and excessive alcohol consumption traditionally have been considered the main risk factors for head and neck squamous cell carcinoma (HNSCC). Oral and oropharyngeal squamous cell carcinoma (OPSCC) are major causes of morbidity, with an estimated annual worldwide incidence of 300,000. Evidence suggests that human papillomavirus (HPV) infection is also an independent risk factor, especially for OPSCC. [1][2][3][4][5][6] Most of the available data on HPVassociated SCC were generated in the United States and Europe. The incidence of HPV-associated malignancies, such as carcinoma of the uterine cervix, varies substantially in different regions of the world; for example, the incidence of HPVrelated cervical/uterine cancer is higher in African and Asian countries than in European countries. 7 Although eastern Asia, including Japan, is known for high epidemics of several oncogenic viral infections, such as Epstein-Barr virus and hepatitis B virus, the status of HPV-related SCC in Asia has not been elucidated.The diagnosis of HPV-related OPSCC can be made using polymerase chain reaction (PCR) analysis to detect HPV DNA 2 ; however, although this is a logical approach, it is quite challenging in clinical practice. Other diagnostic methods are HPV in situ hybridization or quantification of expression of the HPV oncoproteins E6 and E7, which has the major advantage of detecting transcriptionally active HPV. These assays, however, are cumbersome, costly, and require highly trained personnel. 8 A more feasible diagnos...
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